Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

Annotations already declare readOnly/openWorld/non-destructive, but the description adds valuable context beyond them: the fields returned and the auth requirement ('Needs the user's Cotlet API key with access to this app'). Pagination or rate-limit behavior is not covered, so not a 5.

Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

Is the description appropriately sized, front-loaded, and free of redundancy?

The core purpose is front-loaded, but the description is padded with repetition: 'reuse as line items' is restated in 'reuses their names and rates... instead of guessing prices', and the title prefix plus parenthetical about no built-in prices is surplus. Several sentences cover the same ground.

Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

For a simple one-parameter read tool with no output schema, the description explains what is returned (name, description, rate) and the auth prerequisite, which is largely sufficient. Minor gaps remain around result size/sorting behavior, but nothing critical is missing.

Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

Schema coverage is 100% for the single 'search' parameter, so the schema already carries the meaning. The description adds nothing about the search parameter beyond what the schema documents, which is the expected baseline of 3.

Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

Does the description clearly state what the tool does and how it differs from similar tools?

States a specific verb (list) plus resource (saved items) and enumerates the returned fields (name, description, rate). It is clearly distinguishable from the sibling joist_add_item, which writes rather than reads.

Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

Does the description explain when to use this tool, when not to, or what alternatives exist?

Gives clear context for use — reuse saved names and rates on new estimates instead of guessing prices — so the agent understands the intent. It stops short of naming explicit alternatives or conditions where you would not use it, keeping it below a 5.

Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.